N-halo-n-alkyl-o-sulfobenzamides

ABSTRACT

THE INVENTION RELATES TO NOVEL N-HALO-N-ALKYL-O-SULFOBENZAMIDES. THESE COMPOUNDS ARE USEFUL IN BLEACHING COMPOSITIONS AND METHODS. SOME ARE ACTIVATORS FOR PEROXYGEN BLEACHING AGENTS, AND SOME HAVE BLEACHING ACTIVITY THEMSELVES.

United States Patent U.S. Cl. 260-507 R 7' Claims ABSTRACT OF THE DISCLOSURE The invention relates to novel N-halo-N-alkyl-o-sulfobenzamides. These compounds are useful in bleaching compositions and methods. Some are activators for. peroxygen bleaching agents, and some have bleaching activity themselves.

BACKGROUND OF THE INVENTION Detergent and bleaching compositions containing peroxygen bleaches, most commonly sodium perborate, have long been known. They suffer from the disadvantage that perborate has limited bleaching activity at washingtemperature below about 85 C. Variousorganic N-chloro and N-bromo compounds have also been known, and some are low temperature effective bleaches, but they have not been widely used in detergent compositions as they tend to be somewhat harsh in their. effect upon fabrics and may give an undesirable chlorine-type odor in use. If attempts are made to use peroxygen and'chlorobleaches together, they are generally found to cancel each others effect, in that reaction occurs between them with the liberation of molecular oxygen which has no appreciable bleaching effect.

SUMMARY OF THE INVENTION The present invention provides new N-halo-N-alkyl-osulfobenzamides of the formula:

wherein X is chlorine and bromine, R is an alkyl group and M is a cation.

M is preferably an. alkali metal or alkaline earth metal ion.

The alkyl group R generally has from 1 to 20 carbon atoms, and preferably is either a short chain group of 1 to 4 carbon atoms, or, especially if surface-active compounds are desired, a relativelylong chain group of 10 to 18 carbon atoms.

N-chloro compounds are valuable in particular as activators for perborate and like compounds, so that these become etlective bleaching agents attemperatures below about 85 C., for instance in the range from about 38 C. to about 82 C. and especially in the range from about 49 C. to about-60 C. The N-chloro compounds generally have little or no bleaching activity on their own and cause little or no chlorine-type odor in use. Some, at least, of the N-bromo compounds are bleaching agents in their own right, and are generally too reactive to be suitable as activators for peroxy compounds. Both the N-chloro and the N-bromo compounds have bactericidal properties. Those compounds whose alkyl group R is of chain length usual in surface activeagents, for instance from 10 to-' 18 carbon atoms, canhave surface active properties.

The invention therefore provides a bleaching composition comprising an inorganic peroxygen compound and Patented Mar. 28, 1972 "ice an N-chloro compound of the above formula. It also provides a bleaching composition comprising an N-bromo compound of the above formula.

The invention also provides a method of bleaching textile fabrics which comprises treating them in aqueous medium with a compound or composition according to the invention.

DETAILED DESCRIPTION OF THE INVENTION The compounds of this invention can be prepared by any effective method. A convenient starting material is o-sulfobenzoic anhydride, which is treated with an amine R NH (where R is the alkyl group of the intended compound) in the presence of an amine. The amine salt of the resulting N-alkyl-o-sulfobenzamide is converted to the alkali or alkaline earth metal sulfonate salt and this is chlorinated or brominated by treatment with hypochlorous or hyprobromous acid.

The N-chloro compounds of the invention are useful as activators for inorganic peroxygen compounds, such as alkali metal perborates, percarbonates and other salts which release hydrogen peroxide in aqueous solution. They may be used in most solid, especially granular solid, compositions containing such peroxy compounds. Many such compositions, often containing from about 5 to about 35% sodium perborate, are known in the art. Enough (but normally not substantially more than enough) of the N-chloro compound should be included to provide an appreciable and sufiicient activating effect, and good results have been obtained when the molar ratio of activator to peroxy compound is from about 1:20 to 1:1, especially from about 1:10 to 121.5.

The N-bromo compounds are bleaching agents in their own right and are suitable for use in the formulation of granular bleaching compositions, conveniently by mixing them with organic or inorganic builder salts, watersoluble organic surface .active agents or mixtures thereof.

Alkaline builder salts which can be used in conjunction with the N-chloro and N-bromo compounds of the invention include the organic and inorganic builder salts such as sodium pyrophosphate, sodium tripolyphosphate, trisodium and disodium orthophosphates, sodium carbonate, sodium sesquicarbonates, sodium bicarbonate, various sodium silicates, sodium aminopolycarboxylates such as sodium ethylene diamine tetraacetates, sodium ethane-1,1- diphosphonates and the like. Many other inorganic alkaline, neutral or acidic salts may be included as fillers or for processing reasons.

The corresponding salts of other alkali metals, for instance potassium, may be substituted for part or all of the sodium salts.

Inbleaching compositions containing an N-bromo compound of the invention, the N-bromo compound can constitute from about 1% to about of the total composition. Generally it is included in an amount which provides from about 1% to 18%, preferably about 5% by weight of available bromine in the composition.

The meaning of the term percent available bromine is defined by analogy with the term percent available chlorine as applied to chlorine bleaching agents. The latter term represents the percentage by weight of molecular chlorine (GL having equal bleaching power. Since one atom of active chlorine in an N-chloro compound and in hyprochlorites has the same activity as one molecule of molecular chlorine (i.e., two atoms) the percentage available chlorine stated is, by weight, twice the percentage of. active chlorine in the compound or composition, and .correspondingly the percentage of available bromine N-bromo-N-methyl-o-sulfobenzamide monohydrate con- ,tains 21.8% (active) bromine by weight, whichis expressed as 43.6% available bromine.

Detergent compounds which can be employed in conjunction with N-chloro and N-bromo compounds of the invention include water-soluble organic detergents such as soap, anionic synthetic detergents, and nonionic, zwitterionic and cationic detergents. Preferred compositions are based on soaps or anionic sulfonate or sulfate detergents, such as alkyl benzene sulfonates, alkyl sulfates, olefine sulfonates and many others well known in the art. Often nonionic detergents such as fatty alcohol or alkylphenol-ethylene oxide condensates, fatty acid alkanolamides and the like are also incorporated. The usual minor components of detergent compositions may also be present such as suds boosters or detergents, soil suspending agents, corrosion inhibtors, bleach-stable optical brighteners, colors and perfume materials. A suitable ratio of water-soluble detergent to builder salt is from 10:1 to 1:10, and preferably from 1:1 to 1:5.

The N-halo compounds of the invention can also be used for the purposes described above in abrasive or other hard surface cleansers. They have good bactericidal properties and may be used in dishwashing compositions for use in automatic dishwashing machines.

The invention is illustrated by the following examples:

EXAMPLE I Sodium N-chloro-N-methyl-o-sulfobenzamide N-methyl-o-sulfobenzamide was prepared by reacting o-sulfobenzoic anhydride with methylamine and treating the resulting amine salt with Amberlite IR 120 (I-1+) resin. 32.6 g. of the N-methyl-o-sulfobenzamide were dissolved in 200 ml. of water and the solution was neutralized with sodium hydroxide. 480 ml. of 0.42 molar hypochlorous acid (from distillation of a mixture of commercial sodium hypochlorite and boric acid) were added and the mixture was stored for 3 hours at room temperature and then overnight at 4 C. On evaporation of the solution to a small volume the N-chloro body crystallized. This material (39.4 g.) was filtered and dried. On analysis there was found (percent): C, 33.25; H, 3.2; N, 4.75. C H ClNNaO S,H O requires (percent): C, 33.15; H, 3.1; N, 4.85.

EXAMPLE II Sodium N-bromo-N-methyl-o-sulfobenzamide 5 g. of the acid N-methyl-o-sulfobenzamide as prepared in Example I were dissolved in 50 ml. of water and the solution was neutralized with sodium hydroxide. 150 ml. of 0.16 molar hydrobromous acid (prepared by treating bromine water with mercuric oxide and distilling the filtrate) were added and the mixture was stored at room temperature for two hours. Evaporation to dryness gave the N-bromo body (7.3 g.) in microcrystalline form. On analysis there was found (percent): C, 28.1; H, 2.65; N, 3.9. C H BrNNaO S,H requires (percent): C, 28.75; N, 4.2.

EXAMPLE III Sodium N-chloro-N-hexadecyl-o-sulfobenzamide 3 g. of o-sulfobenzoic anhydride were added to a solution of 3.9 g. of hexadecylamine and 2.5 ml. of triethylamine in 40 ml. of anhydrous benzene. The mixture was heated under reflux for 3 hours and stored at room temperature overnight. Evaporation to dryness gave triethylammonium N-hexadecyl-o-sulfobenzamide, which was recrystallized from ethanol. The yield was 7.9 g.

This salt was dissolved in ethanol-water (1:9) and converted to the free sulfonic acid by treatment with Amberlite IR 120 (H+) resin. Neutralization with sodium hydroxide followed by evaporation to dryness gave the corresponding sodium salt which was recrystallized from acetone. This material g.) was suspended in 125 ml. of water, and 34 ml. of 0.45 molar hypochlorous acid (prepared as in Example I) were added. The mixture was stirred at 35 C. until it became clear (3 hours). The N-chloro body was isolatedby lyophilization as an amor- EXAMPLE IV A control washing solution (A) was prepared containing 0.5% by weight of the following detergent-bleaching composition (the proportions being by weight).

Linear alkyl benzene sulfonate 14.0 Sodium toluene sulfonate 1.4 Sodium tripolyphosphate 36.7 Sodium silicate 5.8 Coconut monoethanolamide 1.5

Sodium perborate tetrahydrate 20.5

Sodium carboxymethyl cellulose 0.8 Sodium sulfate 9.5 Perfume, brightener, minor components, etc 1.8 Moisture 8.0

A solution (B) contained in addition 5% and a solution (C) contained 20%, by weight of the detergent composition, of the compound of the formula:

These proportions correspond to 14 and 56 molar percent respectively, referred to the perborate.

Standard tea stained cloth swatches were treated in the solutions and the percentage stain removal measured. Three test conditions were employed:

(i) 10 minutes agitation at 49 C.,

(ii) 16 hours soaking beginning at 49 C. and allowing to cool naturally to room temperature,

(iii) heating over a period of 1 hour from 49 C. to

82 C. and then agitating for 10 minutes.

Percentage stain removal figures are given below:

Solution A WasIIiing condition:

Comparison of the results for solutions of compositions of the invention B and C with the control solution. A show the activating effect of the compounds of the invention, which is as would be expected more marked in conditions 1 and 2 than in condition 3 where the temperature approached that at which perborate alone is known to become fully effective.

EXAMPLE V A washing solution containing 5 g. per liter of the detergent composition of Example IV with the sodium perborate omitted was prepared corresponding to solution A above. To one part was added a sample of sodium N-bromo-N-methyl-o-sulfobenzamide in amount to provide 0.22 g. per liter available bromine, thus forming a solution D. To another part was added a sample of N-bromo benzenesulfonamide (the prior known bleaching agent, commonly named Bromamine-B) in amount to provide the same proportion of available bromine, thus forming a solution B.

When used to wash standard tea-stained cloth swatches for 10 minutes at 49 C. solution D gave 86% stain removal, and solution E gave 57% stain removal.

When used at equivalent concentration in this test procedure the corresponding N-chloro-N-methyl-o-sulfo benzamide gave stain removal results indistinguishable 4. The compound of claim 2 wherein R is alkyl of from those given by the detergent composition in the from to 18 carbon atoms. absence of bleaching agent, viz about to 5-. The compound of claim 1 wherein X is chlorine What is claimed is: 6. The compound of claim 5 wherein R is alkyl of 1. An N-halo N alkyl-o-sulfobenzamide compound 5 from 1 to 4 carbon atoms. having the structural formula 7. The compound of claim 5 wherein R is alkyl of from 10 to 18 carbon atoms.

X I OON References Cited 03M R 10 UNITED STATES PATENTS 2,076,217 4/1937 Albrecht wherein X is selected from the group consisting of chlorine and bromine, R is an alkyl of from '1 to about 20 DANIEL D. HORWIIZ, Primary Examiner carbon atoms, and M is a cation. r

2. The compound of claim 1 wherein X is bromine. -S- Cl- X.R.

3. The compound of claim 2 wherein R is alkyl of from 1 to 4 carbon atoms. 

